This invention relates generally to steam separators and deals more particularly with a cyclone type separator having a square inlet opening which is adjustable in size.
Cyclone steam separators utilize centrifugal force to effect impact of the water droplets of an incoming steam-water mixture against the wall of the separator vessel. The water then drains downwardly into a water chamber located at the bottom of the vessel. The steam is less affected by the centrifugal force and rises into a steam chamber at the top of the vessel where it is collected and subsequently supplied to power generating equipment or used for another purpose. In order to impact maximum swirling motion to the incoming steam-water mixture, steam separators typically have inlets which deliver the mixture either tangent to or in a spiral path relative to the cylindrical inside surface of the vessel. In addition, it is desirable for the inlet opening to be square so that the incoming mixture makes straight line contact with the vessel wall rather than point contact as occurs with a circular inlet opening to the separator. Such line contact permits the fluid to flow smoothly along the vessel wall which streamlines the inlet flow and enhances the swirling action to increase the separation effect.
Steam separators that are employed in connection with geothermal wells are supplied with well fluids that vary widely as to their composition, pressure, flow rate, and temperature. For efficient operation, it is necessary for the steam separator to be capable of handling a wide range of flow rates and pressure without appreciable reduction in its ability to effectively separate the steam from the water. In a typical geothermal installation, it has been found that the velocity of the fluid entering the separator should be a minimum of about 160 feet per second in order for the centrifugal force to be great enough to cause impingement of a satisfactory quantity of water against the vessel wall. On the other hand, if the inlet velocity is greater than about 200 feet per second, significant quantities of steam impact against the vessel wall along with the water, and the efficiency of the steam separator suffers accordingly. Therefore, the inlet velocity for a typical steam separator should be maintained within the range of about 160 to 200 feet per second and should be as close as possible to 180 feet per second, which is the ideal velocity for maximum separation effect. In the past, maintaining the inlet velocity within the desired range has been a difficult problem which has severely hampered the efficiency of cyclone steam separators.